let free_coloring_book = vec![
"mercury",
"venus",
"earth",
"mars",
"jupiter",
"saturn",
"uranus",
"neptune"
];
// 1. free_coloring_book堆上数据的地址
println!("address: {:p}", free_coloring_book.as_ptr());
// 2. free_coloring_book栈上的地址
let a = &free_coloring_book;
println!("address: {:p}", a);
let mut friends_coloring_book = free_coloring_book;
// 3. friends_coloring_book堆上数据的地址,和1一样
println!("address: {:p}", friends_coloring_book.as_ptr());
// 4. friends_coloring_book栈上的地址
let b = &friends_coloring_book;
println!("address: {:p}", b);